Everything there says sammykcy - login ok. Last one was "2020-12-10 16:24:10.288 CET
login: ok - sammykcy". There are your requests from Chrome 87 and Chrome 78, which is weird because our browser identifies as Chrome 71 ...
It's like I wrote, your connection requests goes to the server, it's processed fine there, but the reply can't get back to you because something blocks it. Since your browser requests can find their way back, it really sounds like it's a problem with the firewall or something such. Given that there's even a change in browser version, it seems some software is actively messing with things.